.mien_title {
    font-size: 15px;
    text-align: center;
    color: #6dbc0c;
    margin-top: 30px;
    font-weight: normal;
}

.box {
    width: 1200px;
    height: 400px;
    transform-style: perserve-3d;
    margin: 50px auto;
    position: relative;
}

.box img {
    height: 270px;
    width: 400px;
    position: absolute;
    top: 60px;
    transition: all .3s linear;
}

.box:hover .btn {
    opacity: 1;
}

.front {
    left: 0px;
}

.back {
    left: 800px;
}

.active {
    left: 400px;
    transform: scale(1.5);
    z-index: 10;
}

.btns .btn {
    width: 60px;
    height: 60px;
    display: block;
    position: absolute;
    background-color: rgba(0, 0, 0, .5);
    font-size: 50px;
    font-family: "微软雅黑";
    color: rgba(255, 255, 255, .5);
    line-height: 55px;
    text-align: center;
    cursor: pointer;
    z-index: 100;
    opacity: 0;
    transition: opacity .3s linear;
}

.btns .btn:first-child {
    top: 125px;
}

.btns .btn:last-child {
    top: 125px;
    right: 0px;
}